/*
 * $Id: PDFXref.java,v 1.2 2007/08/26 18:56:35 gil1 Exp $ $Date: 2007/08/26
 * 18:56:35 $ This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of the License,
 * or (at your option) any later version. This library is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
 * the GNU Lesser General Public License for more details. You should have
 * received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA
 */
package pdf.handler;

/**
 * <p>
 * This class is used to hold the xref information in the PDF Trailer block.
 * </p>
 * <p>
 * Basically, each object has an id, and an offset in the end file.
 * </p>
 * <p>
 * See the Adobe PDF Manual for more information. This class will normally not
 * be used directly by a developer
 * </p>
 * 
 * @author Peter T. Mount
 * @author Eric Z. Beard, ericzbeard@hotmail.com
 * @version $Revision: 1.2 $, $Date: 2007/08/26 18:56:35 $
 */
public class PDFXref
{

   /*
    * NOTE: Originally an inner class in PDF.java (now PDFDocument) written by
    * Peter Mount for uk.org.retep.pdf
    */

   /**
    * The generation of the object, usually 0
    */
   public int generation;

   /**
    * The id of a PDF Object
    */
   public int id;

   /**
    * The offset within the PDF file
    */
   public int offset;

   /**
    * Creates a crossreference for a PDF Object
    * 
    * @param id
    *            The object's ID
    * @param offset
    *            The object's position in the file
    */
   public PDFXref(int id, int offset)
   {
      this(id, offset, 0);
   }

   /**
    * Creates a crossreference for a PDF Object
    * 
    * @param id
    *            The object's ID
    * @param offset
    *            The object's position in the file
    * @param generation
    *            The object's generation, usually 0
    */
   public PDFXref(int id, int offset, int generation)
   {
      this.id = id;
      this.offset = offset;
      this.generation = generation;
   }

   /**
    * @return The xref in the format of the xref section in the PDF file
    */
   @Override
   public String toString()
   {
      String of = Integer.toString(offset);
      String ge = Integer.toString(generation);
      String rs = "0000000000".substring(0, 10 - of.length()) +
            of +
            " " +
            "00000".substring(0, 5 - ge.length()) + ge;
      if (generation == 65535)
         return rs + " f ";
      return rs + " n ";
   }

} // end class PDFXref

